Astrometry of 59 pulsars: a comparison of interferometric and timing positions

Using the VLA, positions have been measured for 58 pulsars which also have accurate estimates of position based on pulse arrival times. Estimated errors in the VLA positions are typically 0.2 arcsec and are comparable with the errors in positions obtained from the pulse timing analyses. Agreement between the VLA and timing positions is generally good, although systematic discrepancies at the 0.2–0.5 arcsec level are observed. Timing positions based on an MIT ephemeris differ systematically by ∼ 0.2 arcsec from positions based on a JPL ephemeris. A systematic variation of $$\Delta \alpha$$ cos δ with right ascension α between the VLA and both the MIT and JPL timing positions is observed. We can offer no explanation for this latter discrepancy.